[4][5][6] Anti-tobacco movements in Pakistan and in the UK blamed Barton for his participation in a delegation led by British American Tobacco in 2015 to complain about the Pakistani government's decision to increase the size of health warnings on cigarette packs.

[11] He departed this role and became the first Permanent Under-Secretary of State for the newly combined Foreign, Commonwealth & Development Affairs Office and thus Head of HM Diplomatic Service on 2 September 2020.

In 2021, Sir Philip apologised for the treatment of gay staff: “The ban was in place because there was a perception that LGBT people were more susceptible than their straight counterparts to blackmail and, therefore, that they posed a security risk.

I want to apologise publicly for the ban and the impact it had on our LGBT staff and their loved ones, both here in the UK and abroad.”[12] In December 2021, he admitted failing to show leadership after he began a three-week holiday two days before the Foreign Office internally accepted Kabul was about to fall to the Taliban.

[13] In January 2024, he was criticised by the Chair of the Foreign Affairs Select Committee, Alicia Kearns, for being reticent to agree that Israel has a duty under international law to not block water access to Gaza.